Mozilla tracks the work and scheduling of the Core Firefox OS platform in the following wiki:
Once a new version reaches the Code Complete phase within Mozilla, the source code is forwarded to our partners (chip manufacturers, phone manufacturers, carriers). Our partners must perform performing tests, optimizations, customization, and certifications before an update can be released to the public.
Unfortunately, Mozilla does not have control of the manufacturer's releases for commercial devices - you may contact the manufacturer of your Firefox OS device for specific questions about updates and new releases.
You may also contact your phone carrier for further questions about updates and new releases:
